EN ISO 19164:2024

SLOVENSKI STANDARD
01-november-2024
Geografske informacije - Poseben model za notranje prostore (ISO 19164:2024)
Geographic information - Indoor feature model (ISO 19164:2024)
Geoinformationen - Feature-Modell für Innenräume (ISO 19164:2024)
Information géographique - Modèle d'entités intérieures (ISO 19164:2024)
Ta slovenski standard je istoveten z: EN ISO 19164:2024
ICS:
07.040 Astronomija. Geodezija. Astronomy. Geodesy.
Geografija Geography
35.240.70 Uporabniške rešitve IT v IT applications in science
znanosti
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 19164
EUROPEAN STANDARD
NORME EUROPÉENNE
August 2024
EUROPÄISCHE NORM
ICS 35.240.70
English Version
Geographic information - Indoor feature model (ISO
19164:2024)
Information géographique - Modèle d'entités Geoinformationen - Feature-Modell für Innenräume
intérieures (ISO 19164:2024) (ISO 19164:2024)
This European Standard was approved by CEN on 16 June 2024.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 19164:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 19164:2024) has been prepared by Technical Committee ISO/TC 211
"Geographic information/Geomatics" in collaboration with Technical Committee CEN/TC 287
“Geographic Information” the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by February 2025, and conflicting national standards
shall be withdrawn at the latest by February 2025.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 19164:2024 has been approved by CEN as EN ISO 19164:2024 without any modification.

International
Standard
ISO 19164
First
Geographic information — Indoor
edition
feature model
2024-08
Information géographique — Modèle d'entités intérieures
Reference number
ISO 19164:2024(en) © ISO 2024
ISO 19164:2024(en)
© ISO 2024
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
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CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 19164:2024(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms. 2
4.1 Abbreviated terms .2
4.2 UML notation.3
5 Conformance . 3
6 General . 3
7 Relationship with the existing International Standards . 3
8 Indoor Feature Model . 5
8.1 Indoor top features .5
8.2 Indoor space features .7
8.3 Indoor entity features .10
8.4 Constructive features .11
8.5 Attached features . 13
8.6 Geometric and topological information . 15
9 Extension mechanism of IFM .15
9.1 General . 15
9.2 Attribute hooking . . . 15
9.3 Subclasses . 15
Annex A (normative) Abstract test suite . 17
Annex B (normative) Data dictionary . 19
Annex C (informative) The referenced relationship with BuildingModel of CityGML 3.0 .34
Annex D (informative) The referenced relationship with IFC .38
Annex E (informative) The referenced relationship with IndoorGML 1.1 .42
Bibliography .43

iii
ISO 19164:2024(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 211, Geographic information/Geomatics, in
collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/TC 287,
Geographic Information, in accordance with the Agreement on technical cooperation between ISO and CEN
(Vienna Agreement).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
ISO 19164:2024(en)
Introduction
Various location-based indoor applications, such as indoor navigation, indoor car parking and indoor
emergency response, are increasingly involved in daily lives and the management of public buildings. These
applications need information on indoor features (such as floors, rooms, doors and windows) and their
spatial associations to describe the environment inside a building. Accordingly, many application systems
and related standards have been developed in recent years.
[4]
OGC CityGML 3.0 is designed as a universal information model that defines object types and attributes
which are useful for a broad range of applications. For the building model, CityGML focuses on the
semantic definitions of buildings and their parts (e.g. walls, roofs, dormers, doors, windows, etc.) and the
representation of the relations between those features. However, CityGML does not specify strict rules as to
[7]
which semantic objects have to be included in a specific Level of Detail (LoD) model. Although the CityGML
model can be extended by the Application Domain Extension (ADE) mechanism by adding new object types
or new properties for specific applications, it is possible to specify different ADEs for different information
communities. Every ADE may add their specific properties to the same CityGML feature type as they can all
[6]
belong to the same substitution group. These CityGML feature types can also have the problem of semantic
heterogeneity in sharing and intergrading datasets.
[4]
OGC IndoorGML 1.1 defines the representation and exchange of indoor navigation network models. It aims
to establish a common schema for indoor navigation applications by modelling the topology and semantics
[2]
of indoor spaces, which are needed for the components of navigation networks. An IndoorGML document
contains external links to referenced objects specified in other data sets such as CityGML and IFC (Industry
[2]
Foundation Classes), where the objects in the external data set include geometric information.
The Industry Foundation Classes (IFC) (ISO 16739-1), an open international standard for Building
Information Model (BIM) data, provide detailed 3D geometries and rich semantics to describe architectural
components and engineering constructions of buildings. IFC aims to cover the whole project lifecycle, i.e.
the "plan", "design", "construct", "operate" and "maintain" phases of buildings with more than 600 classes
in different categories. However, IFCs contain too much architectural information and are too complex to be
[11]
used in their current format for indoor emergency situations. It is not necessary to use all these classes
[9]
for a specific application such as indoor navigation. However, some information on the architectural
components and engineering constructions of buildings defined in IFC can be extracted to describe
the attributes of indoor features used in location-based indoor applications to describe indoor spatial
environments to help people to implement their works or plans efficiently.
ISO/TS 19166 provides a conceptual framework for mapping BIM to Geographic Information Systems
(GIS) with three mapping mechanisms, Perspective Definition (B2GPD), Element Mapping (B2GEM) and
LOD Mapping (B2GLM). It focuses on the definition of BIM to GIS conceptual mapping requirements and
framework without a bi-directional mapping method and the definition of physical schema. It cannot be
used directly to guide which indoor features are to be extracted from BIM to describe indoor environments
for location-based indoor applications. Different information communities can set different rules for the
mapping from BIM to GIS and then produce GIS databases with different indoor features for the same
building. This would make the sharing and integration of databases difficult.
[5]
OGC Indoor Mapping Data Format (IMDF) provides a generalized, yet comprehensive model for any indoor
location, providing a basis for orientation, navigation and discovery (19-089r1). IMDF mainly focuses on the
contents of individual indoor features related to navigation issues and does not define a general structure of
these indoor elements to cover the relationship between indoor spaces or features.
Therefore, a relatively independent and concise indoor feature model is needed for describing the required
features of an indoor spatial environment for location-based indoor applications such as indoor navigation,
indoor addressing, indoor car parking and indoor emergency response. This model could provide a common
reference to guide the collection and organization of indoor spatial information, and serve as the foundation
of a conceptual model for data mapping and sharing among various application systems.
This document defines such an indoor feature model by following the rules of application schema defined
in ISO 19109. A dataset compliant with this document can serve as the common basic database in various
location-based (LBS) indoor applications and facilitate data sharing and integrating among different
platforms or applications. This document can be beneficial in reducing the overlapping efforts in the

v
ISO 19164:2024(en)
production of the basic database of buildings, and it can also be useful in the transfer of indoor-application
platforms or systems with little adjustments from one building to another building based on the common
basic database. The intention is for various stakeholders (including indoor data producers and users
of location-based indoor application systems) to have a unified understanding of these features for the
unambiguous retrieval of information.
Based on this document, a series of profiles can be specified for various location-based indoor applications
for example, a profile for indoor navigation or way-finding by linking with a geometric and topological
relationship specified in IndoorGML, or a profile for a fire emergency by adding the features related to
firefighting emergency utilities.
This document provides two informative annexes to present the class-level referenced relationship between
the Indoor Feature Model and BuildingModel of CityGML 3.0, IFC of ISO 16739-1 and IndoorGML.

vi
International Standard ISO 19164:2024(en)
Geographic information — Indoor feature model
1 Scope
This document specifies a core semantic classification system of essential indoor features to describe indoor
environments required commonly in various location-based indoor applications of buildings. The scope
includes the following:
— semantic description of indoor features and their attributes;
— feature association between indoor features.
The semantic classification system in this document is compatible with the building model defined in
existing related standards. Geometric and topological descriptions of indoor features are not considered in
this document. This document does not apply to other architectural structures, such as tunnels.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 19103, Geographic information — Conceptual schema language
ISO 19107, Geographic information — Spatial schema
ISO 19108, Geographic information — Temporal schema
ISO 19109, Geographic information — Rules for application schema
ISO 19115-1, Geographic information — Metadata — Part 1: Fundamentals
ISO 16739-1, Industry Foundation Classes (IFC) for data sharing in the construction and facility management
industries — Part 1: Data schema
ISO 6707-1, Buildings and civil engineering works — Vocabulary — Part 1: General terms
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
feature
abstraction of real-world phenomena
Note 1 to entry: A feature can occur as a type or an instance. Feature type or feature instance will be used when only
one is meant.
[SOURCE: ISO 19101-1:2014, 4.1.11]

ISO 19164:2024(en)
3.2
feature attribute
characteristic of a feature (3.1)
Note 1 to entry: A feature attribute has a name, a data type, and a value domain associated to it. A feature attribute for
a feature instance also has an attribute value taken from the value domain.
[SOURCE: ISO 19101-1:2014, 4.1.12, modified — Examples 1 and 2 along with Notes 2 and 3 have been
removed.]
3.3
feature association
relationship that links instances of one feature type (3.4) with instances of the same or a different feature type
[SOURCE: ISO 19110:2016, 3.3]
3.4
feature type
class of features (3.1) having common characteristics
[SOURCE: ISO 19156:2023, 3.9]
3.5
indoor entity feature
feature (3.1) constructed as indoor architectural components or features attached for a specific use inside a
building
EXAMPLE Windows, doors, furniture and facilities are indoor entity features.
3.6
indoor space feature
feature (3.1) that contains indoor entity features (3.5) or is used as a place for a specific purpose inside a
building, or both
EXAMPLE Rooms, balconies and pathways are indoor space features.
3.7
indoor map
portrayal of an indoor entity feature (3.5) and indoor space features (3.6) as a digital image or vector file
suitable for display on a computer screen
4 Symbols and abbreviated terms
4.1 Abbreviated terms
BIM building information model
GML geography markup language
HMMG Harmonized Model Maintenance Group
IFC industry foundation classes
IFM indoor feature model
LBS location-based service
OGC Open Geospatial Consortium
UML unified modelling language

ISO 19164:2024(en)
URI uniform resource identifier
4.2 UML notation
In this document, conceptual schemas are presented in the unified modelling language (UML). The specific
profile of UML used in this document is presented in ISO 19103.
5 Conformance
This document defines one conformance class:
— “Indoor Feature Model” (specification target: Indoor Feature Model);
A specification, standard, test suite or test tool claiming conformance to this document shall implement the
conformance class relevant to that specification target.
Conformance with this document shall be assessed using all the relevant conformance test cases specified in
Annex A of this document.
All requirements specified in this document belong to the Indoor Feature Model requirements class, which
is identified by the URI ht tps:// standards .isotc211 .org/ 19164/ -1/ req/ IndoorFeatureModel.
Identifiers of requirements and conformance tests specified in this document are relative to https://
standards .isotc211 .org/ 19164/ -1.
The name and contact information of the maintenance agency for this document can be found at www .iso
.org/ maintenance _agencies.
6 General
The Indoor Feature Model (IFM) defines a unified structure and description of the generic indoor features
which can be understood consistently by users (including indoor data producers, developers and users of
location-based indoor applications). The generic indoor features are the basic components constructing
the spatial environments inside a building, and the feature attributes and feature associations provide
information about these components. One of the applications of IFM is to provide the spatial information
to make an indoor map to represent the spatial layouts of these basic components and their characteristics
visually.
7 Relationship with the existing International Standards
Figure 1 illustrates the relationship between IFM defined in this document and other International
Standards related to indoor data and application schema. This document follows the rules of application
schema defined in ISO 19109. The conceptual schema is presented in UML in conformance with ISO 19103.
IFM refers to relative classes and enumerations defined in ISO 16739-1 (IFC) and CityGML and takes
IndoorGML, CityGML and IFC as the external data sources of topological and geometric information of IFM.

ISO 19164:2024(en)
Figure 1 — Relationship with ISO and OGC standards
Following the rules of the application pattern defined in ISO 19109 on data interchange, Figure 2 shows the
role of IFM in data interchange between supplier data sources and user data sources related to LBS-based
applications.
NOTE Modified from ISO 19109:2015. The unbroken lines show the flow of data. Broken lines denote the role of
the application schema on the data interchange.
Figure 2 — The role of IFM on data interchange

ISO 19164:2024(en)
8 Indoor Feature Model
8.1 Indoor top features
IFM defines the semantic structure of a minimal set of the generic feature types, feature attributes
and feature associations of a building, especially a large public building or office building, with complex
structures, multiple functions and diverse public users (Figure 3). These generic feature types should be
involved as the basic datasets for location-based indoor applications such as indoor navigation for shopping
or car parking, emergency escape, and management of facilities or instruments in a hospital. The building
components which are irrelevant to location-based services are not covered in this model.
A building can span over several connected or disconnected buildings to make up a building complex
(ISO 16739-1). A building complex (BuildingComplex class) is a complex feature (the definition in ISO 19109
applies), which is composed of more than one individual building (Building class). Each building is composed
of multiple floors, also called levels or storeys.
Several floors can have a specific usage or ownership as a building subdivision. Examples of building
subdivisions are commercial floors, office floors and accommodation floors in a building. A floor can
composite several floor subdivisions according to the usage or ownership or both. An example of floor
subdivision is the waiting area, commercial area and boarding area on a floor of an airport.
Each floor is composed of various indoor space features and indoor entity features. Indoor space features
may contain indoor entity features. AbstractIndoorSpaceFeature is an abstract superclass to describe
the common attributes of space feature classes. AbstractIndoorEntityFeature is an abstract superclass to
describe the common attributes of indoor constructive features and attached features.
The detailed descriptions of the attributes of the feature types and their associations shall be in accordance
with the data dictionary of Annex B. Annexes C, D and E present the class-level referenced relationship
between IFM of this document and the BuildingModel of CityGML 3.0, IFC (ISO 16739-1) and IndoorGML 1.1.
Requirement 1  /req/IndoorFeatureModel/BasicInfo
Each indoor top feature type shall use the basic information as specified in B.32.1.

ISO 19164:2024(en)
Figure 3 — Indoor top features

ISO 19164:2024(en)
Requirement 2  /req/IndoorFeatureModel/BuildingComplex
The BuildingComplex class shall be used to describe a group of buildings included in a site, as specified in
Clause B.2.
Requirement 3  /req/IndoorFeatureModel/Building
The Building class shall be used to describe the characteristics of a building, as specified in Clause B.3.
8.2 Indoor space features
AbstractIndoorSpaceFeature is an abstract superclass for describing the common attributes of space feature
classes (Figure 4). Table 1 lists the subclasses of AbstractIndoorSpaceFeature.
Requirement 4  /req/IndoorFeatureModel/AbstractIndoorSpaceFeature
AbstractIndoorSpaceFeature class shall describe the common attributes (as specified in Clause B.5) of
indoor space feature subclasses (as specified in (Figure 4 and Table 1).

ISO 19164:2024(en)
NOTE The classes are designed from a common understanding of these features in the real world and the
descriptions of the classes are based information from References [14], [15], [16], [17] or existing ISO standards.
Figure 4 — Indoor Space Features

ISO 19164:2024(en)
Table 1 — Description of indoor space feature classes
Class Description
Room An internal space in a building intended for specific usages, open or surrounded by walls,
doors, floor surface and ceiling.
The details of Room are specified in Clause B.22.
Balcony A raised platform enclosed by one or more walls, zero or one ceiling and/or balustrade con-
nected to the side of a building, with access from a window or door.
The details of Balcony are specified in Clause B.23.
Pathway A linking space between different places (e.g. different floors, rooms or buildings).
The details of Pathway are specified in Clause B.24.
The Pathway class describes the common attributes of various pathways, including stair, elevator, escalator,
corridor, moving walkway, ramp, etc. in a building. The descriptions of the Pathway and its subclasses are
defined in Figure 5 and Table 2.
Requirement 5  /req/IndoorFeatureModel/Pathway
The Pathway class shall describe the common attributes of pathway subclasses as specified in Figure 5 and
Table 2.
Figure 5 — Pathway class and subclasses

ISO 19164:2024(en)
Table 2 — Description of subclasses of Pathway
Class Description
Stair A vertical pathway allowing occupants to walk (step) from one floor level to another floor
a
level at a different elevation.
The details of Stair are specified in Clause B.25.
Elevator A conveyor transport device for carrying people and freights (vertically) between floors in a
building, also called a "lift.
The details of Elevator are specified in Clause B.26.
Escalator A vertically-moving stair used as a conveyor transport device for carrying people between
floors in a building.
The details of Escalator are specified in Clause B.27.
MovingWalkway A slow-moving conveyor pathway that transports people across a horizontal or inclined
plane.
The details of MovingWalkway are specified in Clause B.28.
Ramp A vertical pathway which provides a human circulation link between one floor level and
a
another floor level at a different elevation. A ramp normally does not include steps.
The details of Ramp are specified in Clause B.29.
b
Corridor A narrow and enclosed circulation space that gives access to rooms or other spaces.
The details of Corridor are specified in Clause B.30.
Bridge An aerial pathway built within or between buildings to allow people or vehicles to traverse
from one side to the other.
The details of Bridge are specified in Clause B.31.
8.3 Indoor entity features
AbstractIndoorEntityFeature is an abstract superclass for describing the common attributes of the
subclasses (Figure 6). Table 3 lists the subclasses of AbstractIndoorEntityFeature.
Requirement 6  /req/IndoorFeatureModel/AbstractIndoorEntityFeature
The AbstractIndoorEntityFeature class shall describe the common attributes (as specified in Clause B.6) of
constructive features and attached features, which are defined as subclasses (as specified in Figure 6 and
Table 3).
ISO 19164:2024(en)
Figure 6 — Indoor Entity Features
Table 3 — Description of indoor entity feature classes
Class Description
AttachedFeature Features attached to a specific space in a building related to the special usages
(see 8.5).
The details of AttachedFeature are specified in Clause B.7.
ConstructiveFeature Features are constructed as the inherent components of a building, which are
related to LBS applications in a building (see 8.4).
The details of ConstructiveFeature are specified in Clause B.13.
8.4 Constructive features
The ConstructiveFeature class describes the common attributes of some constructive features related to LBS
applications (including wall, celling, railing, slab, etc.) in a building (Figure 7). Table 4 lists the subclasses of
ConstructiveFeature.
ISO 19164:2024(en)
Requirement 7  /req/IndoorFeatureModel/ConstructiveFeature
The ConstructiveFeature class shall describe the common attributes of constructive features in a building,
as specified in Figure 7 and Table 4.
Figure 7 — ConstructiveFeature class and subclasses

ISO 19164:2024(en)
Table 4 — Description of subclasses of ConstructiveFeature
Class Description
Wall A vertical construction that bounds or subdivides a space and usually fulfils a
a
loadbearing or retaining function.
The details of Wall are specified in Clause B.14.
Door A construction for closing an opening intended primarily for access or egress or
a
both.
The details of Door are specified in Clause B.15.
Window A construction for closing a vertical or near-vertical opening in a wall or pitched
a
roof, which will admit light and can provide ventilation.
The details of Window are specified in Clause B.16.
Column (pillar, GB) A structural member of slender form, usually vertical, that transmits
a
to its base the forces, primarily in compression, that are applied to it.
The details of Column are specified in Clause B.17.
Ceiling A construction covering the underside of a floor or roof, and providing the over-
head surface of an enclosed space, often to conceal structural members or ser-
a
vices.
The details of Ceiling are specified in Clause B.18.
Beam A horizontal, or nearly horizontal, structural member that is capable of with-
b
standing load primarily by resisting bending.
The details of Beam are specified in Clause B.19.
Slab A construction providing the lower support (floor) or upper construction (roof
b
slab, ceiling) in any space in a building.
The details of Slab are specified in Clause B.20.
Railing A frame assembly adjacent to human circulation spaces and at some space
b
boundaries where it is used in lieu of walls or to compliment walls.
The details of Railing are specified in Clause B.21.
8.5 Attached features
The AttachedFeature class describes the features attached to a specific space related to special usages
(including facility, furniture, etc.) in a building (Figure 8). Table 5 lists the subclasses of AttachedFeature.
Requirement 8  /req/IndoorFeatureModel/AttachedFeature
The AttachedFeature class shall describe the common attributes of attached features in a building, as
specified in Figure 8 and Table 5.

ISO 19164:2024(en)
Figure 8 — AttachedFeature class and subclasses
Table 5 — Description of subclasses of AttachedFeature
Class Description
Facility A movable or unmovable instrument or equipment installed and utilized within
a building, making an activity (e.g. action, operation) easier.
The details of Facility are specified in Clause B.8.
Furniture A furnishing such as a table, desk, chair or cabinet, which is permanently or
a
non-permanently attached to a building structure.
The details of Furniture are specified in Clause B.9.
Sensor A device that measures a physical quantity and converts it into a signal which
a
can be read by an observer or by an instrument.
The details of Sensor are specified in Clause B.10.
Robot A machine that can do the work of a person and that works automatically or is
controlled by a computer.
The details of Robot are specified in Clause B.11.

ISO 19164:2024(en)
8.6 Geometric and topological information
Geometric and topological descriptions of indoor features are not considered in this document. In case of an
external data source whose geometric and/or topological model matches IFM feature types, the geometric
and/or topological information of the external data sources can be linked with IFM-based datasets during
implementation.
Geometric and related information of IndoorGML, CityGML and IFC-based data may be linked to IFM if needed.
Permission 1  /per/IndoorFeatureModel/topology
IFM may link with a geometric and topological relationship defined in IndoorGML for the implementation of
indoor navigation or wayfinding.
Permission 2  /per/IndoorFeatureModel/CityGMLObject
IFM may reference links to CityGML objects for further geometric and semantic modelling and take CityGML
data as one of the data sources for implementation.
Permission 3  /per/IndoorFeatureModel/IFCObject
IFM may reference links to IFC objects for further geometric and semantic modelling and take IFC data as
one of the data sources for implementation.
9 Extension mechanism of IFM
9.1 General
An Application Domain Extension (ADE) can be modelled directly in the XML schema or can be generated by
extending the UML model of IFM with application-specific information and later deriving the XML schema
from it.
Permission 4  /per/IndoorFeatureModel/Extension
Therefore, similarly to CityGML, ADEs may use elements from the IFM to associate extra attributes to the
existing classes and derive application-specific subclasses.
IFM accepts two types of extension: attribute hooking and subclasses.
9.2 Attribute hooking
Every IFM feature class has a GML "hook" of the form
"GenericApplicationPropertyOf" in its XML schema definition. For example,
GenericApplicationPropertyOfFloor can be used to attach a new attribute “numberOfElevator” to Floor class.

substitutionGroup="GenericApplicationPropertyOfFloor"/>
9.3 Subclasses
The IFM can be extended with new classes for new feature types as subclasses of the existing IFM classes.
The subclasses can also use the same stereotype «FeatureType» as the IFM classes. As shown in Figure 9,
the IFM Door class is extended with a new feature type “FireproofDoor” as a subclass with new attributes
“fireProtectionLevel” and “fireResistantTime”.

ISO 19164:2024(en)
Figure 9 — Example for subclass extension

ISO 19164:2024(en)
Annex A
(normative)
Abstract test suite
A.1 General
This annex specifies an Abstract Test Suite which shall be passed by any implementation claiming
conformance with this document.
A.2 Conformance Test Class: Indoor Feature Model
A.2.1 General
The URI identifier of this conformance class is: https:// standards .isotc211 .org/ 19164/ -/ 1/ conf/
IndoorFeatureModel.
The URI identifier of this requirements class is: https:// standards .isotc211 .org/ 19164/ -/ 1/ req/
IndoorFeatureModel.
Tests identifiers below are relative to https:// standards .isotc211 .org/ 19164/ -/ 1.
A.2.2 Basic description
a) Test ID: /conf/IndoorFeatureModel/BasicInfo
b) Test purpose: Verify that each indoor top feature type shall use the basic description as specified in the
data dictionary of B.32.1.
c) Test method: Inspect the content of the data intended to support IFM. Each indoor top feature instance
shall use the basic description as specified in the data dictionary of B.32.1. Test passes if constraint
evaluates to be "true".
A.2.3 BuildingComplex
a) Test ID: /conf/IndoorFeatureModel/BuildingComplex
b) Test purpose: Verify that the BuildingComplex class is used to describe a group of buildings included in
a site, as specified in Clause B.2.
c) Test method: Inspect the content of the data intended to support the indoor feature model, check that
BuildingComplex instance contains information as specified in Clause B.2. Test passes if constraint
evaluates to be "true".
A.2.4 Building
a) Test ID: /conf/IndoorFeatureModel/Building
b) Test purpose: Verify that the Building class is used to describe the characteristics of a building as
specified in Clause B.3.
c) Test method: Inspect the content of the data intended to support IFM, check that Building instance
contains the characteristics of a building as specified in Clause B.3. Test passes if the constraint
evaluates to be "true".
ISO 19164:2024(en)
A.2.5 AbstractIndoorSpaceFeature
a) Test ID: /conf/IndoorFeatureModel/AbstractIndoorSpaceFeature
b) Test purpose: Verify that the AbstractIndoorSpaceFeature class is an abstract superclass to describe the
common attributes of indoor space feature classes, which are defined as subclasses in Table 1.
c) Test method: Insp
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